Free NCLEX-RN Pharmacology Practice Questions
Free NCLEX-RN pharmacology and parenteral therapies practice questions with full rationales — medication safety, adverse effects, and nursing implications.
A nurse is teaching a client newly prescribed warfarin for atrial fibrillation. Which statements should the nurse include? Select all that apply.
- A.Keep your vitamin K intake from foods like leafy greens consistent rather than suddenly changing it
- B.Use a soft toothbrush and an electric razor to reduce bleeding
- C.Have your INR checked regularly so the dose can be adjusted
- D.Double the dose on any day you forget the previous day's dose
- E.Take an over-the-counter aspirin daily for extra heart protection
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Correct answers: A, B, C
Warfarin teaching centers on keeping the effect steady and avoiding bleeding. Vitamin K is the antidote, so wild swings in green-vegetable intake destabilize the INR; the rule is consistency, not avoidance. Routine INR checks let the provider fine-tune the dose. Bleeding precautions (soft toothbrush, electric razor) lower injury risk. Doubling a missed dose stacks anticoagulation and invites hemorrhage. Adding daily aspirin layers another bleeding risk on top of warfarin and should not be started without provider direction.
Why the other options are wrong
- D. Doubling up dangerously increases anticoagulation; a missed dose is reported, not doubled.
- E. Aspirin adds antiplatelet bleeding risk and should not be self-started while on warfarin.
Key takeaway: On warfarin, keep vitamin K intake consistent, monitor INR, take bleeding precautions, and never double doses.
A nurse is preparing to hang the first dose of IV ceftriaxone, a high-alert IV potassium infusion, and a heparin drip for different clients. Which safety actions apply to safe parenteral medication administration? Select all that apply.
- A.Perform an independent double check with a second nurse for the heparin drip and the IV potassium
- B.Administer IV potassium chloride by rapid IV push to save time
- C.Use a programmable infusion pump for the high-alert continuous infusions
- D.Stay with the client for the start of the first dose of ceftriaxone to watch for an allergic reaction
- E.Verify the client using two identifiers before giving each medication
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Correct answers: A, C, D, E
High-alert drugs (heparin, concentrated IV potassium) carry a high chance of serious harm, so they get extra guardrails: an independent double check by a second nurse and delivery through a programmable pump that controls the rate. Potassium is never pushed IV, because a bolus can stop the heart; it always runs diluted and pump-controlled. First doses of antibiotics warrant staying to watch for an allergic reaction. And two-identifier verification applies to every medication, every time.
Why the other options are wrong
- B. IV potassium is never given by push; a rapid bolus can cause fatal cardiac arrest, so it must be diluted and infused slowly.
Key takeaway: High-alert IV drugs need double checks and pumps; potassium is never IV push, and two identifiers apply to every med.
A client recovering from surgery received IV morphine 4 mg twenty minutes ago. The nurse now finds a respiratory rate of 7 breaths/min, pinpoint pupils, and difficulty arousing the client. After ensuring the airway and stimulating the client, which medication does the nurse anticipate administering?
- A.Flumazenil
- B.Naloxone
- C.Acetylcysteine
- D.Protamine sulfate
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Correct answer: B
Match the reversal agent to the drug class. The triad of slowed respirations (under 8/min), pinpoint pupils, and sedation after a recent opioid dose is opioid-induced respiratory depression. Naloxone is the opioid antagonist that reverses it. Because naloxone has a shorter half-life than many opioids, the nurse keeps monitoring for re-sedation and titrates to restore breathing without erasing all analgesia. Airway support and stimulation come first, then the antagonist.
Why the other options are wrong
- A. Flumazenil reverses benzodiazepines, not opioids.
- C. Acetylcysteine is the antidote for acetaminophen toxicity.
- D. Protamine sulfate reverses heparin, not opioids.
Key takeaway: Opioid overdose presents with respiratory depression and pinpoint pupils and is reversed with naloxone.
A client on digoxin for heart failure reports nausea, anorexia, and seeing yellow-green halos around lights. The morning potassium is 3.0 mEq/L. Which understanding guides the nurse's response?
- A.The low potassium increases the risk of digoxin toxicity, and these symptoms suggest toxicity
- B.The symptoms are expected effects of digoxin and require no action
- C.The high potassium is protecting the client from toxicity
- D.The visual changes are unrelated to digoxin and point to a stroke
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Correct answer: A
Low potassium and digoxin are a dangerous pair: hypokalemia lets digoxin bind more tightly to the cardiac cells, so toxicity can appear even at normal drug levels. The triad here, GI upset (nausea, anorexia) plus the classic yellow-green halos, is textbook digoxin toxicity. With a potassium of 3.0, you connect the cues: hold the dose, check a digoxin level, and treat the hypokalemia, because correcting potassium reduces the toxic effect. Always read the potassium alongside the digoxin.
Why the other options are wrong
- B. Halos and GI symptoms are toxicity signs, not benign expected effects.
- C. 3.0 mEq/L is hypokalemia, which raises toxicity risk; it is not high and not protective.
- D. Yellow-green halos are a recognized digoxin toxicity sign, not a stroke indicator.
Key takeaway: Hypokalemia potentiates digoxin toxicity; yellow-green halos plus GI symptoms signal it.
A client with asthma has been taking oral prednisone 40 mg daily for three weeks. The prescriber writes an order to discontinue the drug today. What is the nurse's most appropriate action?
- A.Administer the final dose and stop the drug as ordered
- B.Hold the drug and clarify the order, because systemic steroids are tapered, not stopped abruptly
- C.Give the dose every other day for one more week without contacting the prescriber
- D.Switch the client to an equivalent dose of inhaled albuterol
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Correct answer: B
Systemic corticosteroids taken longer than about two weeks suppress the adrenal axis, so they must be tapered, never stopped suddenly. Here the client has had high-dose prednisone for three weeks, which meets that threshold. Abrupt withdrawal can trigger adrenal crisis: hypotension, weakness, hypoglycemia, and shock. An order to discontinue outright is unsafe, so the nurse holds it and clarifies before acting. Confirming a questionable order is within the nurse's responsibility and prevents harm.
Why the other options are wrong
- A. Following an unsafe order verbatim does not relieve the nurse of accountability; abrupt stop risks adrenal crisis.
- C. Nurses cannot independently change a dosing schedule; any taper requires a prescriber order.
- D. Albuterol is a rescue bronchodilator, not a substitute for the systemic anti-inflammatory effect of steroids.
Key takeaway: Systemic steroids used beyond roughly two weeks are always tapered to avoid adrenal crisis.
A client with bipolar disorder takes lithium and reports new nausea, coarse hand tremor, and slurred speech that started yesterday. The client mentions starting a low-sodium diet and a thiazide diuretic last week. The lithium level is 1.8 mEq/L. Which interpretation should guide the nurse's next action?
- A.The symptoms are expected side effects and the level is therapeutic
- B.Low sodium intake and the thiazide are raising the lithium level into the toxic range
- C.The client is showing signs of a manic relapse unrelated to the drug
- D.The level is subtherapeutic and the dose should be increased
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Correct answer: B
Lithium and sodium compete for reabsorption in the kidney, so anything that lowers sodium makes the body retain more lithium. A new low-sodium diet plus a thiazide diuretic (which causes sodium loss) both push lithium upward. The therapeutic range is roughly 0.6 to 1.2 mEq/L, and 1.8 mEq/L is toxic. Coarse tremor, GI upset, and slurred speech are classic moderate-toxicity signs. The nurse must connect the dietary and drug changes to the rising level and treat this as toxicity.
Why the other options are wrong
- A. A level of 1.8 mEq/L exceeds the therapeutic ceiling of about 1.2 mEq/L, and coarse tremor signals toxicity.
- C. The symptom cluster and the elevated level point to a pharmacologic cause, not a mood relapse.
- D. The level is above range, so raising the dose would worsen the toxicity.
Key takeaway: Sodium loss raises lithium levels, so low-salt diets and diuretics predispose to lithium toxicity.
A client with heart failure takes digoxin and furosemide. The client reports nausea, blurred yellow-tinged vision, and seeing halos around lights. The apical pulse is 52 beats/min and irregular. Which laboratory value most likely explains the client's worsening risk for digoxin toxicity?
- A.Potassium 2.9 mEq/L
- B.Sodium 138 mEq/L
- C.Calcium 9.2 mg/dL
- D.Magnesium 2.1 mg/dL
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Correct answer: A
Low potassium sensitizes the heart to digoxin, so hypokalemia worsens toxicity even when the digoxin level itself is unchanged. Furosemide is a potassium-wasting loop diuretic, which sets up this pairing. A potassium of 2.9 mEq/L is well below the 3.5 to 5.0 range. The visual changes (yellow-green vision, halos), nausea, and bradycardia are textbook digoxin toxicity. Correcting potassium reduces the danger, so this value is the key driver.
Why the other options are wrong
- B. Sodium 138 mEq/L is normal and does not potentiate digoxin.
- C. Calcium 9.2 mg/dL is within normal limits; while high calcium can worsen toxicity, this value is normal.
- D. Magnesium 2.1 mg/dL is normal; low magnesium would add risk, but this value is not low.
Key takeaway: Hypokalemia increases digoxin toxicity, and loop diuretics like furosemide cause potassium loss.
A nurse is preparing to administer IV chemotherapy that is a known vesicant. Which actions should the nurse take to promote safe handling and reduce harm? Select all that apply.
- A.Wear chemotherapy-rated gloves and a gown when handling the drug
- B.Verify blood return and patency of the line before and during infusion
- C.Dispose of all chemotherapy waste in the regular trash to save space
- D.Confirm the drug, dose, and route with a second qualified nurse
- E.Know the location of the extravasation kit and antidote protocol
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Correct answers: A, B, D, E
Vesicant chemotherapy can cause severe tissue necrosis if it leaks, and the drugs are hazardous to handlers, so safety layers stack together. Personal protective equipment shields the nurse (A). Checking blood return and patency catches early extravasation (B). Independent double-check of drug, dose, and route reduces fatal dosing errors (D). Knowing the extravasation kit and antidote location lets the nurse respond fast if leakage occurs (E). Hazardous waste must go in designated cytotoxic containers, never regular trash.
Why the other options are wrong
- C. Cytotoxic waste requires special labeled containers; regular trash exposes others to hazardous residue.
Key takeaway: Vesicant chemo safety combines PPE, line patency checks, independent double-check, and extravasation readiness.
A client is receiving total parenteral nutrition (TPN) through a central line. Which findings or actions require the nurse's immediate attention or intervention? Select all that apply.
- A.The TPN bag has run empty and the next bag is delayed an hour
- B.A blood glucose of 312 mg/dL on routine monitoring
- C.The client has a temperature of 38.9 C with chills
- D.The infusion is running on a programmed electronic pump
- E.The TPN solution appears cloudy with visible separation
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Correct answers: A, B, C, E
TPN is a high-dextrose solution delivered into a central vein, so the main dangers are glucose swings and infection. An abrupt stop or gap risks rebound hypoglycemia, so a delayed bag needs intervention; hang dextrose 10% if TPN is unavailable (A). A glucose of 312 mg/dL signals hyperglycemia needing treatment (B). Fever with chills suggests catheter-related bloodstream infection (C). A cloudy or separated bag may be contaminated or precipitated and must not be infused (E). Running TPN on a controlled pump is correct, expected practice.
Why the other options are wrong
- D. Using a programmed infusion pump is the standard safe method for TPN and needs no intervention.
Key takeaway: TPN priorities are preventing glucose swings, watching for line infection, and never hanging a cloudy bag.
A client with a seizure disorder is prescribed phenytoin. During discharge teaching, which statement by the client indicates a correct understanding of self-care with this medication?
- A."I will brush and floss carefully every day and see my dentist regularly."
- B."I can stop the medication once I have gone a month without a seizure."
- C."It is fine to skip a dose if I feel well that day."
- D."A pink or red tinge to my urine means the drug is not working."
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Correct answer: A
Phenytoin commonly causes gingival hyperplasia (overgrowth of gum tissue), so meticulous oral hygiene and regular dental visits are core self-care. The client who describes daily brushing, flossing, and dental follow-up shows correct understanding. Antiepileptics are never stopped abruptly or skipped because that can trigger breakthrough seizures or status epilepticus. A harmless pink-red or brown urine color can occur with phenytoin and does not signal drug failure.
Why the other options are wrong
- B. Stopping an antiepileptic without a taper and prescriber guidance risks breakthrough seizures.
- C. Skipping doses lowers the drug level and can provoke seizures even when the client feels well.
- D. A harmless pink-red or brown urine discoloration can occur and does not indicate treatment failure.
Key takeaway: Phenytoin causes gingival hyperplasia, so diligent oral hygiene and dental care are essential teaching points.
A nurse is caring for several clients receiving IV fluids and antiemetics. Which observations indicate a safe and appropriate plan of care? Select all that apply.
- A.A client with hypovolemia from vomiting is receiving 0.9% sodium chloride
- B.A client on ondansetron has a baseline ECG checked because of QT-prolongation risk
- C.A client receiving rapid 3% saline for routine maintenance fluids
- D.A client on metoclopramide is monitored for restlessness and involuntary movements
- E.A client receiving D5W as the sole resuscitation fluid for hemorrhagic shock
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Correct answers: A, B, D
Match the fluid and the monitoring to the problem. Isotonic 0.9% sodium chloride is the right choice to replace volume lost from vomiting (A). Ondansetron prolongs the QT interval, so a baseline ECG is appropriate (B). Metoclopramide can cause extrapyramidal symptoms, so watching for restlessness and abnormal movements is correct (D). Hypertonic 3% saline is a high-alert fluid for symptomatic hyponatremia, not routine maintenance (C). D5W is hypotonic once dextrose is metabolized and cannot resuscitate hemorrhagic shock (E).
Why the other options are wrong
- C. 3% saline is hypertonic and reserved for severe hyponatremia, not routine maintenance, and is given slowly.
- E. D5W provides free water, not volume expansion, so it cannot treat hemorrhagic shock.
Key takeaway: Safe IV and antiemetic care matches isotonic fluids to volume loss and monitors ondansetron and metoclopramide for known adverse effects.